Oelke, Ervin A.Grava, JanisNoetzel, DavidBarron, DonaldPercich, JamesSchertz, CletusStrait, JohnStucker, Robert2014-12-302014-12-301982https://hdl.handle.net/11299/16906840 pages; includes photographs and drawings. This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu.en-USNewsletter or Bulletin